Pool, 25, was a second-round draft pick by the Browns in 2005 out of Oklahoma. He has been a starting free safety in Cleveland the past three seasons.

But Pool was sidelined by a concussion late last season and missed the Browns’ final five games. Pool, 6-2, 210 pounds, already had a career-high four interceptions prior to the season-ending concussion.

According to the Cleveland Plain Dealer, Pool has had at least four concussions in his five NFL seasons. Perhaps out of concern for Pool’s concussion problems, the Browns did not tender him as a restricted free agent.

With Oshiomogho Atogwe given the lowest tender by St. Louis, the Rams could be exploring their options at free safety.